Which COVID-19 vaccine is best? Pfizer, Oxford, and more – Medical News Today
March 31, 2022
Each vaccine has its own risks and benefits, but those that have been approved for use are effective at reducing risk of a COVID-19 infection. The best vaccine for an individual is one they can access and feel comfortable taking.
The Food and Drug Administration (FDA) has approved or authorized three vaccines: Moderna, Pfizer-BioNTech, and Johnson & Johnsons Janssen. The Centers for Disease Control and Prevention (CDC) recommend getting Moderna or Pfizer-BioNTech if they are available.
However, different vaccines are available globally. Many countries are starting to approve the new Novavax vaccine and the Oxford AstraZeneca vaccine that is common in Europe.
Like all medical treatments and medications, vaccines come with risks and benefits.
The data on COVID-19 vaccines show that side effects are minimal. While there have been rare instances of serious side effects, the risk of adverse events from a COVID-19 infection is much higher.
Read more to learn about the approval status, dosage, efficacy, and side effects of each COVID-19 vaccine.
The Pfizer-BioNTech vaccine, also called COMIRNATY, is an mRNA vaccine.
It uses a lipid, or a fatty acid, to deliver a piece of the viruss genetic code. However, it does not contain the virus rather, it contains a piece of messenger RNA (mRNA) that codes for the viruss unique spike protein.
The body responds to this spike protein as an intruder and develops the immune reaction it needs to fight it. The vaccine teaches the body how to fight the COVID-19 virus when it encounters the real thing.
The vaccines contents leave the body and do not alter a persons genetic code.
It does not contain:
The FDA has approved the vaccine for individuals over the age of 16. It has an emergency use authorization for people over the age of 5 and for booster shots.
The initial series is two injections, at least 21 days apart, and a booster requires a third shot.
The dosage is:
It is safe to mix and match this vaccine with others.
The vaccines side effects are typically mild, and some people report having more side effects after the second vaccine.
They commonly report cold and flu-like symptoms such as:
The side effects usually disappear within a few days. They happen because of the immune systems reaction to the injection, so having side effects shows that the vaccine is working.
According to the CDC, the full series of the vaccine is more than 95% effective at preventing laboratory-confirmed COVID-19 infections in adults who are not immunocompromised and have no documented history of a COVID-19 infection.
In children ages 515 and people with immunocompromising conditions, the vaccine was at least 90% effective.
Among adults without immunocompromising conditions between March 11 and August 15, 2021, the vaccine offered 88% efficacy against hospitalization. This time period extends into the Delta wave of the pandemic.
Preliminary data from Pfizer showed that three doses of the vaccine could neutralize the Omicron variant.
Other research is still ongoing. A 2022 study found that in a lab setting, a booster could offer some immunity to Omicron.
The Moderna vaccine, also called Spikevax, is an mRNA vaccine
Although it works similarly to the Pfizer vaccine, it delivers a slightly higher dose.
Like Pfizer, it contains mRNA that gives instructions for fighting the spike protein on the COVID-19 virus. This produces an immune reaction that trains the body to fight the virus if it encounters it in the real world.
The vaccines contents leave the body and do not alter a persons genetic code. It does not contain any of the following:
The FDA has approved the Moderna vaccine for adults ages 18 and over. It also has an emergency use authorization as a one-dose booster 5 months after receiving another vaccine.
Moderna is not approved for use in children.
The initial Moderna series requires two injections, with a third shot as a booster.
It has earned an emergency use authorization for people over the age of 18. Each dose is 0.5 mL, and the two shots should be at least 28 days apart.
Like the Pfizer vaccine, it is safe to mix and match this vaccine with others.
Because they are both mRNA vaccines, the side effects of Moderna are similar to those of Pfizer.
Some people report mild cold or flu-like symptoms shortly after getting vaccinated with side effects more frequently appearing after the second vaccine than the first. Some common side effects include:
Among adults without immunocompromising conditions between March 11 and August 15, 2021, Moderna was 93% effective against hospitalization due to COVID-19. This time frame includes the Delta wave, but not Omicron.
A 2022 study found that an additional Moderna booster dose could provide some immunity against the Omicron variant while the two-dose series did not. Moderna is working on a booster specific to new variants.
The J&J/Janssen vaccine is a single-shot viral vector vaccine.
Unlike Pfizer and Moderna, it is not an mRNA vaccine. Instead, it works similarly to traditional vaccines.
The vaccine uses a weakened form of a harmless adenovirus that delivers genetic code for the unique COVID-19 spike protein. This creates an immune reaction that prepares the body to fight COVID-19. The vaccines contents leave the body and do not alter a persons genetic code.
It cannot infect a person with COVID-19 or the adenovirus, and it does not contain:
The injection is generally less effective than the Moderna and Pfizer vaccines.
The CDC urges people to choose the mRNA vaccines unless they are inaccessible. While J&J/Janssen is safer than going unvaccinated, it may have worse side effects than other vaccines.
The FDA has approved the vaccine on an emergency use authorization basis for people over the age of 18. It has also given emergency use authorization for a booster at least 2 months after the first dose.
The vaccine is not approved for children or anyone under the age of 18.
The most common side effects of this vaccine include mild cold or flu-like symptoms such as nausea, fever, chills, and muscle aches.
Very rarely, however, a person may develop a blood clot.
The CDC estimates that roughly 3.83 people per million will have this side effect. However, the blood clot rate is much higher with a COVID-19 infection, with as many as 1 in 5 people experiencing a blood clot. Of 18.2 million J&J/Janssen vaccine recipients, just 57, or 1 in more than 300,000, have reported blood clots.
The J&J/Janssen vaccine is a single-dose vaccine. It has an emergency use authorization in the United States for people over the age of 18.
A person can also get a single dose booster, but the CDC recommends choosing Pfizer or Moderna instead. It is safe to mix and match this vaccine with others.
Between March 11 and August 15, 2021, a time period that included the Delta wave but not Omicron, the J&J/Janssen vaccine was 71% effective in preventing COVID-19 hospitalization.
The Oxford AstraZeneca vaccine works very similarly to the J&J/Janssen vaccine.
It uses an adenovirus to deliver the COVID-19 spike protein into the body. This creates an immune reaction that trains the body to fight the virus if it encounters it again.
The AstraZeneca vaccine does not have FDA approval in the United States. However, it is popular in Europe because it is less expensive to produce than mRNA vaccines and is easier to store.
The World Health Organization (WHO) recommends two doses of 0.5 mL each, and the vaccines should be 8 to 12 weeks apart. It is safe to mix and match this vaccine with others.
Some common side effects include:
In rare cases, the AstraZeneca vaccine may cause blood clots. The risk of blood clots from COVID-19 is exponentially higher.
The AstraZeneca vaccine prevents symptomatic infection in 6 out of 10 people. Early trials, prior to Delta and Omicron, showed an 80% efficacy at preventing hospitalization.
The Novavax vaccine uses older vaccine technology specifically, a protein subunit.
This vaccine delivers an antigen synthesized from the COVID-19 spike protein to train the body to fight the virus. It does not contain a live virus, and the spike antigen cannot replicate.
Novavax is not yet approved for use in the U.S., but a request for an emergency use authorization has been submitted. As of November 2021, it is approved for use in Indonesia and the Philippines.
The WHO recommends two 0.5 mL doses given 34 weeks apart.
It is safe to mix and match this vaccine with others.
Side effects include:
In clinical trials, the efficacy of Novavax against mild, moderate, and severe disease was 90%. Researchers do not know if it prevents infection or transmission and are conducting additional research.
There are four types of COVID vaccines in use or in clinical trials:
Current CDC guidelines suggest that vaccines are safe for most people including those who are pregnant, breastfeeding, and have immunocompromising conditions. A person should only avoid a vaccine if they have had an allergic reaction to a specific ingredient in that vaccine.
The availability of vaccines varies from location to location. In areas that offer multiple vaccines, a person can often choose their vaccine. This might require going to a specific provider or scheduling the vaccine for a specific day.
It is usually safer to get the first available vaccine to maximize a persons protection against COVID-19.
All currently approved COVID-19 vaccines are safe for use and reduce a persons chance of severe illness with the virus.
Although all vaccines come with side effects, the risk of side effects from COVID-19 remains much higher. Except for a severe allergic reaction or a known allergy, there is no reason to avoid a COVID-19 vaccine.
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Which COVID-19 vaccine is best? Pfizer, Oxford, and more - Medical News Today